Water contamination in hydrocarbon liquid fuels may originate from many sources. Trace amounts of water exist in fuel due to the refining and purification processes performed at the petroleum refineries. Additionally, water may seep into fuel storage tanks or may form as condensation within storage tanks or delivery trucks. Furthermore, when fuel is placed in a fuel tank of a vehicle, water may form through condensation or may be inadvertently introduced into the fuel tank.
Internal combustion engines burning gasoline-type fuels can accommodate relatively large amounts of water before issues such as poor drivability and stalling occur. However, internal combustion engines burning diesel-type fuels are much less tolerant of water mixed with fuel. These engines typically utilize high-pressure pumps and fuel injection devices for introducing pressurized fuel into the internal combustion engine. The pump and injectors are precision devices that are sensitive to water, which has low lubricity and a corrosive effect on metals. From a performance standpoint, water mixed with fuel can cause roughness in engine operation, loss of power, and poor starting ability, particularly during cold start.
The use of fuel-water separator assemblies within fuel systems of internal combustion engines is known in the art. The fuel-water separator assemblies typically include a water reservoir configured to contain water separated from the fuel. A sensor may be provided within the water reservoir to detect the presence of water and to provide a warning to the operator of the vehicle. The control systems used to monitor the sensor typically include a “debounced” type routine operable to ignore the intermittent activation of the sensor due to the sloshing of water with the movement of the vehicle. As such, typical control systems employing a single sensor provide the ability to sense one level, i.e. a critical level, of water within the fuel-water separator.